SECTION
INTRODUCTION
  (t) Close and fasten all doors and covers in the top and bottom surface of the wing. Be sure all Dzus fasteners have the proper tension grip.

 (9) WING GUN DISMOUNT-Reverse the procedure outlined for gun installation. After the initial installation it will not be necessary to remove the front adapter from the wing. To release the gun from the adapter, simply pull the toggles down and release the eye bolts, allowing the locking plates to be moved outward. The guns can be easily removed and installed without disturbing the setting as long as the adjustment elements are not tampered with.

 (10) GUN ACTION REMOVAL-The gun action may be removed with the gun in the wing as follows ;

  (a) Remove the leading edge cover plate.

  (b) Unscrew the blast tube from the retainer on the gun barrel at the leading edge of the wing.

  (c) Unbutton the gun access door.

  (d) Detach the feed chutes from the inboard and center guns and the link chute from the outboard gun.

  (e) Loosen the front mounting bolt slightly to allow the front adapter to pivot on the yoke.

  (f) Remove the rear mounting bolt.

  (g) Through the port in the upper wing skin, loosen the nut as far as possible in order to drop the gun down to clear web 5. Release the toggle, swing the saddle over the gun, and allow the rear adapter to swing under the gun.

  (h) Remove the back plate. from the gun and withdraw the bolt, driving pin, and gun barrel, with the barrel extension and lock frame, from the gun.

 (11) GUN HEATER-The gun heater installation consists of flexible ducts in the leading edge of the wing panels, which take warm air from the oil cooler and coolant radiator exit air duct and transmit it to both sets of wing guns by means of flexible neoprene. impregnated asbestos tubing. This gun heater unit prevents gun freezing.

d. PYROTECHNIC INSTALLATION.

 (1) A type M-8 Very Pistol is provided for signaling purposes. This pistol is carried in a bracket below the front edge of the pilot's seat. When firing this pistol, the following directions should be adhered to as there is a large recoil and this recoil must be absorbed by the pilot's wrist and forearm.

  The arm holding the pistol should be bent at the elbow in such a manner that the forearm lies across the chest with the pistol pointing upward at an angle of approximately 45 degrees. The top of the pistol is rotated so that it is lying on its side with the top away from the chest. When fired, the recoil is absorbed by the bent arm and the pistol is pushed away from the body. 		        
  NOTE:  
The recoil force of the pistol is slightly greater than that of the .45 caliber service pistol.

  To load the pistol, simply push up on the breech unlocking lever and the pistol will break or open similar to opening a breech for an ordinary double barreled shotgun. To unload, reverse the procedure and pull out fired cartridge. The top forward finger grip is merely to pull the pistol out of the mount.
  
  CAUTION:  
The cartridges are colored, make sure that the pistol is loaded with the correct cartridge for the signal intended.

2. OXYGEN INSTALLATION.

 a. OXYGEN CYLINDER-The type F-1 oxygen cylinder has a capacity of 1,000 cubic inch and will withstand approximately 750 psi. pressure. The cylinder rests on rubber padding in a cradle installation mounted on the center line at the bottom of the fuselage. The cylinder is anchored in the cradle by a rubber-lined strap. It may be removed through the fuselage access door by disconnecting the oxygen and filter lines at the check valve forward of the cylinder and releasing the retaining strap by means of the turnbuckle.

 b. OXYGEN REGULATOR.-The oxygen regulator is located near the floor of the cockpit on the right side of the airplane, adjacent to the pilot's seat.

 c. FILLING OF THE OXYGEN CYLINDERFill the cylinder at the filler valve, located inside at the lower right corner of the fuselage access door. The filler valve contains a one-way check which -permits flow through the filler line in the direction of the cylinders only. Fill the oxygen cylinders to a pressure of 450 psi. The filler valve closes itself.
  
  WARNING:  
The entire system shall be completely free of:

  (1) Oil and grease, to avoid the danger of spontaneous combustion and explosion when in contact with high pressure oxygen.

  (2) Water, to prevent the freezing of the oxygen equipment at low temperatures.

  (3) Other foreign matter, to prevent the contamination of the oxygen with dust and odors.

  d. See Fig. 117 for a diagrammatic view of the oxygen installation.

3. WEIGHT AND BALANCE.

 The following charts give the weight and center of gravity location in percent of the Mean Aerodynamic Cord for several different loading conditions.